Boston Marathon Bombing

Video collected during the investigation of the 2013 Boston Marathon bombings shows the bombers Tamerlan and Dzhokhar Tsarnaev on the day of the bombings. Release of the video helped lead to the brothers' identification.

Video surveillance of Tamerlan and Dzhokhar Tsarnaev.

On April 15, 2013, as runners from around the world were cheered by thousands of spectators lining the streets for the 117th Boston Marathon, two self-radicalized brothers, Tamerlan and Dzhokhar Tsarnaev, executed the largest terrorist attack on U.S. soil since 9/11. They detonated two powerful explosives near the finish line, killing three people and injuring more than 500 others. 

The attacks set off a furious manhunt. Three days after the bombing, the FBI released photos and video of the two suspects.  
Later that night, the terrorists drove to the Massachusetts Institute of Technology (MIT) campus, where they shot and killed MIT Police Officer Sean Collier and attempted to steal his service weapon. The terrorists then carjacked a vehicle, kidnapped its driver, and forced him to drive to a gas station, robbing him of $800 along the way.  
After the driver escaped, the terrorists drove to Watertown, Massachusetts, where they detonated several improvised explosive devices (IEDs) and engaged in a firefight with law enforcement officers. 

During the stand-off, Dzhokhar drove the carjacked vehicle at three officers, attempting to kill them, and ran over Tamerlan as he fled. Tamerlan died from injuries sustained at the scene. Dzhokhar was taken into custody after he was discovered hiding in a boat in the backyard of a Watertown residence. 
Dzhokhar, who was 19 years old at the time, was charged with use of a weapon of mass destruction resulting in death and conspiracy, along with 29 additional terrorism-related charges.  
In the high-profile federal trial, the prosecution team introduced over 1,000 exhibits and called more than 100 witnesses to the stand, including 14 victims who suffered amputations after the bombings.

Others testifying included family members of those killed, survivors and eyewitnesses, experts in the areas of fingerprints, DNA, bombs, and ballistics, law enforcement officers, and terrorism experts. Prosecutors also cross-examined nearly 50 defense witnesses.   

Some additional notable elements that helped shape the investigation:

  • FBI Boston’s Evidence Response Team (ERT)—working with teams from the Boston Police Department, the Massachusetts State Police, and the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF)—spent nine days processing 12 square blocks near the bomb scenes. About 176 FBI Laboratory and ERT personnel were deployed to Boston to assist.
  • Evidence technicians processed more than 3,500 pieces of evidence and shipped 2,749 items to the Laboratory in Quantico, Virginia, for further analysis.
  • More than 33 terabytes of digital information were collected, including photos and video from the public via a special digital tip line developed to support the investigation.
  • Linguists spent more than 2,500 hours translating material to support the investigation and trial.
  • The Victim Services Division deployed 10 victim specialists from around the country to support Boston’s specialists in providing support and resources to the victims and their families.

A jury found Dzhokhar guilty on all 30 counts in the indictment. He was sentenced to death in June 2015.

Fireworks Found in Dzhokhar Tsarnaevas Dormitory Room

Opened and emptied fireworks found in Dzhokhar Tsarnaev’s dormitory room.


Dias Kadyrbayev, 19, and Azamat Tazhayakov, 19, both of New Bedford, Massachusetts, were charged with, among other offenses, conspiring to destroy evidence; namely, a laptop computer and backpack containing fireworks. 

A third accomplice, Robel Phillipos, of Cambridge, Massachusetts, was charged with willfully making materially false statements to federal law enforcement officials during a terrorism investigation.